The objectives of the proposed research are to study in three aspect: (1) the turnover of membrane proteins in synaptic junctions related to neurotransmitter release, (2) the regulation of endorphin biosynthesis in brain, and (3) the regulation of neural activity by the phosphorylation of membrane proteins. Each aspect will be examined in brain areas isolated from control or opiate-treated animals. We have already found that acute or chronic treatment of rats with morphine or other opioid results in altered turnover of some membrane proteins, and in altered phosphorylation of some membrane proteins. We propose during this year to relate the effects of opiates on turnover and phosphorylation of specific membrane proteins and to try to determine the function of these proteins.